Hello,
I've been using mythtv for about 10 years for OTA recording, with few issues. For the first time I am trying to watch and later record IP streams.

This is my 5th late night trying to get this done. After working on my main system with no luck, I have made a clean install of v29 on ubuntu for testing. I have found several postings with similar problems, but few if any who have posted that they have been successful with this. My process, following several guides is:

I pull the channel with no problem from the m3u file. One channel, for my simple test case m3u file. When watching live tv in the myth frontend, it hangs after 40 seconds (the limit I set). It shows a partial lock (TL_). The OSD shows correctly, with my channel number and name. Never locks.

The m3u file works great in VLC. The format is correct, as far as I know for mythtv, as it shows up fine when I watch live tv, but it will never lock or show anything but a black screen.

I was unable to get streaming working following the IPTV pages on the mythtv wiki, including the nasa streams. Perhaps they are not active any more.

I confirmed that IPTV streaming in v29, on my setup, works after finding some random m3u files on the internet inking to streams. I have two sets of channels in my m3u file:
a - four channels from my IPTV provider
b - four channels found on the internet, local ABC news streams.

group b work fine! group a do not.
group a channels try to lock, but result in "Partial Lock TL__", as before.

Both group a and group b work fine when opened on VLC. Looking at the codec on VLC, all channels are H264-MPEG-4 AVL. Some are 1280 x 720, some are lower resolution. This tells me that there is not an issue with mythtv not handling some odd codec or something like that.

In my m3u local file, the working group b entries are all links to .m3u8 files. Group a entries look like direct links to streams. Could this be the problem? For example:

#EXTM3U
#EXTINF:-1,101 - group B channel
http://###### link to group b stream ##########live/live.m3u8
#EXTINF:-1,200 - group A channel
http://########### link to group A channel ######QB/10212

when I follow the working group b .m3u8 links, it contains more info, such as:
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=678000,RESOLUTION=768x432,CODECS="avc1.77.30, mp4a.40.2"

VLC handles both types with no problem. Is there something evident here about why group a will not lock?